The Brain Defense: neuroscience in court

Neuroscience plays a role in the courtroom just like partial fingerprinting and DNA. It is a field with which many struggle. Is it true when someone says: “my brain made me do it?” Is that person hearing voices or simply making excuses?

It is tempting to think that indeed, they make up excuses to avoid punishment. However, as parents do we not cover our newborn’s head to make sure it doesn’t lose heat? Do we not watch like hawks that their heads do not get hurt because their fontanelles are not closed yet? Do we not tell our kids to wear helmets when biking, rollerblading, and playing other types of sports? Instinctively we protect brains and instinctively we also doubt brains.

Let me give you an example that you can look up online to research further: sexsomnia. The first time that I heard about a man raping a woman while he was asleep I didn’t believe it. I still struggle with it. Part of me thinks that there are natural inhibitions so that out-of-character actions do not happen. Yet it does.

Sexsomnia is a condition in which a person will engage in sexual activities while asleep. From the Sydney Morning Herald: “Dr Matthew Walker: “the cortex – the thinking, planning, awareness part of the brain – gets switched off. But the brain stem, the part responsible for the basic urges like the drive to eat or have sex is still working. By this stage, the sexsomniac is acting completely without inhibition. Because the lower level of the brain is amnesic, he or she will have no memory of what he or she has done.” Some brain parts are active, some do not register anything. This plays a role in Kevin Davis’ book on neuroscience as well.

The author uses the story of Herbert Weinstein. The indictment for the crime of murder in the second degree alleges that on Jan 1, 1991, Weinstein, normally a peaceful man, murdered his wife, Barbara. Weinstein strangled her in their 12th floor apartment in Manhattan (NY), and threw her body from a window to make her death look like suicide. Weinstein’s defense attorney argued that Weinstein lacked criminal responsibility for killing his wife because of a mental disease or defect. (See, CPL 250.10; Penal Law § 40.15.)

The case centers on the issue of free will versus irresistible impulses. As Aristotle said: to be found morally responsible we need the intent to act, the knowledge that we are committing a criminal act, and the awareness of the consequences. Weinstein’s was the first case in the United States in which a judge allowed a scan showing a defendant’s brain activity to be admitted as evidence to support a claim of innocence.

The book discusses various cases and refers to the works of many neuroscientists who study the prefrontal cortex. The prefrontal cortex is the last portion of the brain to fully develop. In other words, the last part to develop is the part that covers our ability to reason and to oversee consequences. Adolescents do not develop these complex decision-making and planning skills that adults have until they are 22-25 years old. That is why we no longer sentence juveniles to death or life without parole. We recognize the incompleteness of their brains and with that the incompleteness of their reasoning. This is the line of thought when it comes to brain injuries.

The book looks at Traumatic Brain Injuries (TBI) caused by car accidents, falling, concussions, etc. as well. Exterior circumstances such as having been a POW, child abuse, etc. play a huge role in controlling impulses. But how big a role? And if you are not guilty of this crime by reasons of insanity can you relapse? What are the risks? Not everyone with a brain injury has trouble resisting certain impulses. The book also shows studies that compare brain activity in people with and without an injury/mental impairment.

We make decisions based on what we have experienced and have learned. If all is well we reflect on the short and long-term consequences. Not just for us but for others as well. We apply logic and reason to counter a purely emotional decision. How exactly we weigh all issues involved is hard to explain.

The author has written a fascinating book. It is a must read for everyone interested in crime and criminology, why people act the way they do, and where neuroscience has been able to answer some of our questions.

The book is very well written. The cover hints at a textbook but it doesn’t read like one. Clinical and legal issues are explained in plain English. There are extensive notes in the back.

Highly recommended reading!

Note: I received an advance uncorrected proof in exchange for an honest review.